Safety bindings are known which engage the boot only adjacent to its heel, as well as safety bindings which can be imagined to be transferred toward said heel. Most of these bindings engage lateral hardware or extend into openings from below. The protruding hardware can easily be damaged. Modern skiing techniques involve also the danger that such hardware is caught by the other boot or by stones. Openings extending from below cannot be kept clean in such an arrangement. Bindings are known which are tightened in the longitudinal direction of the ski. These bindings comprise plates which may have various forms and are screw-connected to the sole of the boot and engaged with binding elements which serve to transmit force, to control the ski, and to release the binding. This has the disadvantage that only a small space is available so that the contact surfaces are small and the pressure per unit of area is high, particularly as the required holding forces increase as the distance between the gripping surfaces decreases in relation to the length of the ski. Stronger forces and a higher pressure per unit of area involve stronger and heavier gripping elements, which must not have inserts of plastics material and are susceptible to damage and may become impressed into the plates. The function of these bindings is adversely affected soon and they cannot be reset.
It is an object of the invention to provide a safety ski binding which may be used in conjunction with a conventional boot comprising a heel, sole, and shank. Experience has shown that best results can be obtained with such boots. It is another object of the invention to provide a ski binding which can hold and release the heel of the skiing boot independently of the state of maintenance of the binding and in which the forces required for a release vary in a constant range which is independent of the adjustable force which tends to restore the binding when the ski has been subjected to a transverse impact. An additional object of the invention is to provide a ski binding which is structurally simple and may be provided with robust components which can be made in part of plastics material so that they are light in weight.